Arcless switch



2 Sheets-Sheet 1 F I G 2 LLI T I I I-PT "T I L I l i J F I G. 4

INVENTOR. BY 5 76m yflzm ATTORNEYS July 10, 1962 A. J. TONASZUCH a ARCLESS SWITCH FllGd May 18, 1959 FIG?) FIG.5

A. J. TONASZUCH ARCLESS SWITCH 2 Sheets-Sheet 2 FIGS INVENZOR. X'W BY ATTORNEYS July 10, 1962 Filed May 18, 1959 United States Patent 3,043,941 ARCLESS SWITCH Anthony J. Tonaszuch, 167 West St., Randolph, Mass.

Filed May 18, 1959, Ser. No. 813,947 1 Claim. (Cl. 200-152 The present invention relates to mechanical switching and, more particularly, to a novel mechanical switch taking advantage of the trouble free operation characteristic of mercury junctions but preventing any disadvantage by reason of arcing occuring during making and breaking.

The object of the present invention is to provide a novel switch comprising an external component defining a seat, and an internal component within the seat, one of the components presenting a substantially continuous insulating surface that provides at least one electrical contact, the other of the components providing a substantially continuous insulating surface interrupted by an aperture retaining a mass of mercury. The operation is such that the switch is actuated when the mercury is in contact with the contact and is deactuated when the mercury is spaced from the contact. Arcing between the mercury and the contact is prevented by portions of the components providing the insulating surfaces.

Other objects of the present invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the product possessing the features, properties and relation of elements that are exemplified in the following detailed disclosure, and the scope, of which will be indicated in the appended claim.

For a fuller understanding of the nature and objects of the present invention, reference should be had to the following detailed description in connection with the accompanying drawings wherein:

FIG. 1 is a side elevation of a preferred switch embodying the present invention;

FIG. 2 is a front elevation of the switch of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 1, taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is aside elevation of another switch embodying the present invention;

FIG. 5 is a front elevation of the switch of FIG. 4;

FIG. 6 is a cross-sectional view of the switch of FIG. 4, taken substantially along the line 66 of FIG. 5;

FIG. 7 is a side elevation of a further switch embodying the present invention;

FIG. 8 is a front elevation of the switch of FIG. 7; and

FIG. 9 is a cross-sectional view of the switch of FIG. 7, the section being taken substantially along the line 9-9 of FIG. 8.

Generally, each of the embodiments of the present invention herein disclosed comprises an outer stationary casing providing a seat therein and an inner rotatable core snugly received by the bearing. The seat in the casing presents a continuous insulating surface interrupted by a plurality of apertures. Each aperture has a restricted mouth through which a mass of mercury contacts the core but is prevented from escaping from the aperture. The inner core presents a continuous surface interrupted by a plurality of conducting contacts. The shape of the continuous surface of the seat and the shape of the continuous surface of the core conform closely to each other, the surfaces throughout the regions of the apertures and the contacts being spaced from each other by a distance preferably less than one thousandth of an inch. In accordance with the present invention, the arrangement is such that when any mercury mass and contact are only slightly spaced apart they are separated by insulating portions of the casing and the core. In consequence, the tendency for arcing to occur between any 2 mercury mass and any contact is minimized by the presence of a dielectric therebetween.

The switch of FIGS. 1, 2 and 3 comprises a stationary casing 20 and a rotatable core 22. Casing 20, which is composed of plastic, provides a seat 24 for core '22. Core 22, which is composed of plastic, is prevented from moving axially within seat 24 by a pair of steel rings 26 and 28 that are sprung into grooves at the periphery of core 22. Provided within casing 20 are apertures 30 and 32, which extend from the outer periphery of outer casing 20 into communication with seat 24. As is best shown in FIG. 3, each of apertures 30 and 32 includes an outer internally ribbed portion 34 of relatively large outside diameter, an inner smooth portion 36 of relatively small outside diameter and a restricted mouth 38. Within the well defined by portion 36 is a mass of mercury 40, which is accessible to core 22 through aperture 38. Mercury 40 is kept an appropriate pressure by a screw 42, which is turned into an internally threaded collar 44 within portion 34 of aperture 30. Extending through core 22 is a brass rod 46, which is disposed substantially in the plane of apertures 30 and 32. The extremities of rod 46 are shaped to continue the cylindrical. surface provided by core 22. The arrangement is such that when core 22 is rotated into actuated position, an electrical path is provided through thepressure screw and mercury of aperture 30, through rod 46 and through the mercury and pressure screw of aperture 32. Thus, the pressure screws serve as terminals of a direct or alternating current power source (not shown). And when core 22 is rotated into deactuated position, the outer extremities of rod 46 are spaced from the mercury of apertures 30 and 32. The tolerance between core 22 and seat 24 is 'sufficiently small to preclude arcing between the extremities of rod 46 and the mercury in apertures 30 and 32, by virtue of the interposition of insulating portions of'the casing and the core at the moment before contact between the rod and the mercury is made or at the moment after contact between the rod and the mercury is broken.

In the form shown casing 20 is aflixed to a mounting plate 48, which in turn may be afiixed to a panel or other suitable support. As shown in dotted lines at 50, a second casing similar in all respects to casing 20 may be added for the purpose of providing a double-pole, doublethrow rather than a single pole, double-throw switch.

The switch of FIGS. 4, 5 and 6 comprises a stationary casing '54 and a rotatable core 56. Casing 54 includes a forward portion 58 providing a seat 60 for core 56 and a rearward portion '62 for retaining core 56 within seat 60. Extending through rearward portion 62 in parallelism with the axis of core 56 are four apertures 64, 66, 68 and 70. Each of these apertures is similar in all respects to aperture 30 of the switch of FIGS. 1, 2 and 3, encompassing a sleeve, a screw and a mercury mass similar to sleeve 44, screw 42 and mercury mass 38. Extending rearwardly from rearward portion 62 is a hub 72 that provides an aperture 74 similar in all respects to aperture 30, encompassing a sleeve, a screw and a mercury mass similar to sleeve 44, screw 42 and mercury mass 38. Core 56 includes an insulating disk 76 that is positioned within seat 60 in abutment against rearward portion 62 of casing 54, a'conducting element 78 having a disk portion that is registered with disk 76, a pin' portion 80 that projects through an opening in disk 76 and a shaft portion 82 that projects into contact with the mercury mass of aperture 74. Conducting element 78 is connected in any suitable way with the remainder of shaft 56 that projects from forward portion 58 of casing 54. Pin 80 is spaced from the axis of core 56 a distance substantially equal to the distance from this axis of apertures 64, 66, 68 and 70. The operation of the switch of FIGS. 4, 5

a 3 and 6 is such that the mercury masses provided by a selected one of apertures 64, 66,68 and 70 may be caused to make an electrical connection with the mercury mass of aperture 74. i

The switch of FIGS..7, 8 and9 Comprises a stationary casing 86 and a rotating core 88. Casing 86 includes a forward portion 90 providing a seat 92 for core 88 and a rearward portion 94 for retaining core 88 within seat 92. At positions around core 88 are four apertures 90, 92, 94 and 96 which are similar in all respects to aperture 30 of the switch of FIGS. 1, 2 and 3, encompassing a collar, a pressure screw and a mercury mass of the type shown at 44, 42 and 4t). Projecting through rearward portion 94 is'an aperture 98 encompassing a collar, pressure screw and mercury mass of the same type. Core 88 includes a barrel 100, composed of an insulating material, a pin 102 is composed of a conducting material, and

arod 194 composed of a conducting material that con- 7 above description or shown in the accompanying drawing shall be interpreted in an illustrative and not in a limiting sense.

What is claimed is:

A 'switch comprising an external component having a substantially continuous insulating surface providing a seat, an internal componenthaving a substantially continuous insulating surface snugly received in said seat, said external component and said internal component being relatively movable, at least an aperture in one of said components communicating with said seat, said aperture providing a restricted mouth region and an enlarged shank region, said shank region presenting internal threading, an externally threaded screw turned into said internal threading,- a mass of mercury positioned in said mouth region between said screw-and said seat, at least an electrical terminal in the other of said components, said electrical terminal presenting a surface substantially geometrically continuous with the remainder of the adjacent surface of said other of said components, said electrical terminal making contact with said mass at given relative positions of said components, said electrical terminal being insulated from said mass when spaced therefrom by portions of said components providing said insulating surfaces, increments of said one of said components being spaced from increments of said other of said components contiguous therewith by a given tolerance, said increments of said one of said components being spaced from said electrical terminal when con ti-guous therewith by said given tolerance, said given tolerance being lessthan .001 inch.

ReferencesCited in the file of this patent UNITEDSTATES PATENTS Hotine -c. Dec. 16, 1958 

